Webscraping Proxy Library for Scrapy (github.com)

Python library for dealing with proxies in your Scrapy project

Wow. Doesn't even bother to link to Scrapy itself.

You may also look to this project: https://github.com/nfx/slrp - rotating open proxy multiplexer

Not free & no personal association with them, just a former happy customer -- https://proxymesh.com/ -- paid/hosted "rotating" proxies with additional features available like session-pinning, location selection, etc. I haven't used it in years now but it was a great service back then; it looks like it has probably only improved since then, and the owner/developer was helpful and great to work with as well.